Texas Rep. Ralph M. Hall, the oldest member of Congress, has promised this will be his final campaign.

He's said it before — several times, in fact — and gone on to run again anyway. But this time, some Texas operatives think the 17-term Republican incumbent could very well be running his last race, though not by choice. By all available metrics Hall, who turns 91 a couple of months after the March 4 primary, is in serious political trouble. He faces a six-candidate primary field in a state that allows for a runoff. And two of his challengers outraised him in the last three months of 2013.

One of those rivals, former U.S. Attorney John Ratcliffe, has political connections, the capacity to self-fund and is running an organized campaign. But what's earned Ratcliffe more attention than anything is the $400,000 he loaned his own campaign. Even without it, he still outraised Hall in fourth quarter contributions.

"I wouldn’t be shocked at all, with that kind of money, that this guy kicks this thing to a runoff," one unaligned Texas GOP operative said.

Hall faced similar challenges in the past two cycles but avoided a runoff by taking just less than 60 percent of the vote each time. Several Republican operatives reached for comment on this story said if he's forced into a late spring runoff this time around, all bets are off.

The reason this year could be different is Ratcliffe, a U.S. attorney under President George W. Bush and current partner at the law firm of former Attorney General John Ashcroft. Ratcliffe has professional consultants on his payroll and is up with a positive TV ad introducing himself to northeast Texans.

www.youtube.com/watch?v=fP4xGZi9XaA

This is a sprawling district, encompassing the Louisiana, Arkansas and Oklahoma borders, plus the prohibitively expensive media markets in the Dallas suburbs. Although Ratcliffe and his campaign declined to say how much money was involved in the buy, he has the funds to mount a TV blitz in the rural areas.

Hall is going up this week with TV and radio spots of his own, but his campaign declined to characterize the buy's size.

Republican strategist Ed Valentine, a Hall ally, said the congressman's 33-year bond with 4th District voters has proved strong before and will again on March 4.

"He’s very in touch with the district, and he votes right," Valentine said. "He’s voted against both bailouts. In 32 years, he’s never voted for a tax increase. ... He doesn’t really have any votes that are detrimental to his re-election."

Hall is well-regarded for his constituent services and boasts enviable name identification. Voting for Ralph Hall after 17 terms is a northeast Texas habit, so much so that voters did not bat an eye when Hall switched parties in 2004. Since then, he hasn't won a general election with less than 64 percent of the vote.

That was a potentially vulnerable time for Hall. His switch to the GOP in early 2004 came amid House Majority Leader Tom DeLay's mid-decade redraw of Texas' congressional lines. After a two-decade drift, Hall was one of the Lone Star State's last conservative Democrats to make the jump to the GOP. Yet in 2004, Hall won 77 percent of the vote in the GOP primary and took 68 percent in the general.

In 2010, Hall faced a self-funded challenger who outpaced Ratcliffe's year-end contributions. The next cycle brought a threat from the Campaign for Primary Accountability, a super PAC. Hall beat back both attempts.

In an interview with CQ Roll Call, Ratcliffe, a rising star in local GOP circles, made his case for challenging Hall in 2014 rather than waiting one more term to seek a hypothetically vacant seat. Ratcliffe said Hall has made the pledge to retire before without following through. He called for change and "bold and energetic leadership" to take on the country's fiscal woes.

But in not allowing Hall a graceful exit, Ratcliffe risks burning bridges with the longtime lawmaker's political friends.

"I'm less concerned about feelings within the party,” Ratcliffe said. “If I’ve offended ... party officials by running against an incumbent, then I think that’s their problem. I don't think voters are offended by that at all."

The race for the 4th District is receiving little attention in Texas beyond the local constituencies. For the first time in more than a decade, ambitious Republicans are running in multiple open-seat races for statewide office. Most of the political class is completely consumed with those campaigns . It is hard to imagine a cavalry coming to Hall's aid next month.

Without available polling, it's unknown whether Hall will finally meet his match.

Regardless, if Ratcliffe is not successful this cycle, he will have already built a strong base to mount another campaign when — or if — Hall retires.